1. Field of the Invention
This invention relates to a novel weightlifting bar that is adapted to receive weight plates thereon to form a barbell, and particularly to a novel barbell bar wherein the overall center of gravity of the bar, when symmetrically loaded with free weight, is always lower than the portion of the bar that is grasped and raised by the user.
2. Description of the Prior Art
Weightlifting bars are used by body builders and power lifters during exercises to increase their skeletal muscle mass and to increase their strength. The bars are used as handles to lift replacable disc-shaped weight plates that are attached at both ends of the bar. When the handle is short and the weighted bar can be manipulated with one hand, the weighted bar is called a dumbbell. When the handle is long and the weighted bar must be manipulated with two hands, this weighted bar is called a barbell. There are many different designs of these bars for use as barbells and dumbbells. Such bars are described in U.S. Pat. Nos. 1,013,782 to J. Koch; 2,508,567 to L. G. Dymeck; 2,722,419 to S. Tarapczynski; and 3,588,102 to L. F. Gifford.
Generally, weightlifting bars are formed from straight pieces of hollow tubes or solid rods and have straight end sections which are adapted to receive the weight plates. In order to adapt the bars for particular exercises, portions of the bars are bent so that the user's hands grasp the bar at particular angles with respect to the remainder of the bar, either to better exercise certain muscles or to avoid undesired stress on certain muscles or on the user's torso generally.
U.S. Pat. No. 4,605,222 to G. L. Shannon describes a weightlifting bar that may be considered a special purpose dumbbell designed for lifting relatively light loads with one or two hands. The bar described in the Shannon patent includes a straight short center section, a pair of short handles that extend radially at right angles from each end of the center section, and a pair of side sections extending at an acute angle with respect to the center section from the extended ends of each of the handles. The center of gravity of this weight-loaded bar is centered between the handles both laterally and longitudinally; that is, at about the middle of where the user ordinarily grasps the bar. Because of its configuration and the relative position of the center of gravity, this prior bar, when loaded with weights, can be used to perform a variety of exercises without undesirable torque loading on the user's wrists. If the center of gravity of the loaded bar is not centrally disposed between the handles at all times, greater or lesser torque would be experienced by the user as the movement of the user's wrists rotates the weight center outward and upward.
When using a barbell with very heavy weight loads, as in exercises known as a military press, a clean-and-jerk, and a snatch-and-jerk, better weight stability is desirable, especially when the user is at or near the limit of his lifting capability. An imbalance for any reason might cause the bar to tip and weight plates to shift off the one side and then off the other side of the bar, with the possibility of injury to the user and/or to a bystander.
In another set of exercises, the weight-loaded bar is used in conjunction with a weightbench. In these exercises, the bar is placed in a horizontal position on a holder comprising the bench. Weight plates are loaded symmetrically onto the bar. The user positions himself on the bench, raises the loaded bar off the holder, performs the desired exercise, and then returns the bar to the holder. The user is usually at or near the limit of his lifting ability and usually performs the exercises to the limit of his endurance. In both of these situations, upon reaching his limits, the user loses some measure of control over the loaded bar and the bar might tip, even when an assistant is present to help guide the bar. Usually, when using a bench, collars are not used to keep the weight plates from slipping off the side sections. So, especially in such situations, tipping this bar might result in weight plates slipping off the bar, with the possibility of injury to the user and/or the assistant.
When such heavy loads are being used, it is desirable for the weight-loaded bar to have a center of gravity that is substantially lower than the portion of the bar that is grasped by the user during the exercise. A lower center of gravity provides more stability, thereby helping to maintain the weight plates in position on the bar, and also gives the user more control over the weight-loaded bar. However, when raising the weight-loaded bar from an arms-down position to an arms-up position, the bar rotates. A low center of gravity in prior barbells produces increasing and undesirable torque and stress in the user's grasp as the weight center of the barbell is rotated outward and upward.